Separable attachment plug



SEPARABLE ATTACHMENT PLUG Filed June 25, 19::

' 2s a 2': I 28 INVENTOR v ment plugs, and more 17. The projecting Patented Feb. 26, 1929.

UNITED STATES PATENT OFFICE.

GEORGE J. MEU'IEIR. OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER-HAMMER MFG. 00., OF MILWAUKEE,

WISCONSIN, A CORPORATION OF WISCONSIN.

SEPARABLE ATTACHMENT PLUG.

Application filed June 25, 1923. Serial No. 647,441.

This invention relates to separable attachparticularly to the base members thereof.

An ob j ect of the invention is to provide an attachment plug base having comparatively few parts, which may be assembled in an easy and convenient manner.

Another object is to provide an attachment plug base in which the several parts have interlocking connection whereby all of the parts may be held in assembled position by a single fastening means.

Another object is to provide an attachment plug base in which the parts are adapted to e held in proper position preferably without the use of screws, rivets, or the like.

Other objects and advantages will hereinafter appear.

In the drawing,

Figure 1 is a vertical sectional view of an attachment plug base constructed in accordance with the present invention, the parts heing in assembled position;

igs. 2 and 3 are top and bottom plan views thereof, respectively;

Fig. 4 is a side elevation of the plug base, the shell being omittedfor purposes of illustration; and

Figs. 5 and 6 are top plan and vertical sectional views, respectively, of the insulating washer.

Referring to the drawing, the block 10 of insulation is provided with an upwardly projecting portion 11, and extending vertically through the block 10 are a pair of openings 12 and 13, shoulders 14 and 15 being provided at the lower portion of the base'to reduce the size of the openings, as indicated at 16 and ortion 11 is provided with channels 18 and 19 on opposite sides thereof registering with the openings 12 and 13, respectively. 1

A terminal contact finger 20 is provided with a substantially U-shaped upper end, the vertical portions 21 and 22 thereof being arranged to engage the channels 18 and 19, and the horizontal portion 23 bein adapted to rest upon the upper surface 0 the projection 11. At the base of the (projection 11 the tact finger, said tongue also engaging the opening 35 therein to accommodate the cross sectional contour of the projecting port-ion 11 and.to clear the vertical portion 22 of contact finger 20.

The washer 25 insulates the shell from the contact finger 20 whereas said shell is in direct engagement with the contact finger at the horizontal and vertical portions 31 and 32 thereof, respectively, said vertical portion 32 preferabl being sprung outwardly slightly to provi e firm engagement with the shell when it is forced into position by the latter. The shell 34 is provided with a tongue 36 adapted to engage the channel 18 to prevent relative rotation of the shell and insulating block. When the shell has been placed in position the lower edge thereof is spun or turned inwardly into an annular groove 37 in the block 10, as shown in full lines in Fig. 1. The

shell is also screw-threaded, as indicated at 38 to permit the plug to be screwed into a socket of the usual type. With the parts thus assembled the same are securely and permanently held in proper position without the use of attaching screws, embedded rivets, or the like. .The manner of supporting the contact finger 20 provides a strong and reliable contact for engagement with t e center contact in an ordinary socket, and the contact finger 30 has a very lar e area of contact with the shell 34, to there y insure proper electrical connection between said contact finger and the cooperating contact of a socket.

The lower ends of the contact fingers are bent or curved inwardly to be protected by the shoulders 14 and 15, as indicated at 39 and 40. Thus when the terminal contacts of the usual co-operating lug member or cap (not shown) are inserte into the openings 16 and 17 the same will be guided into proper contacting relation with the contact fingers 30 and 20, respectively; the latter being provided with bosses or projections 41 and a2 adapted to snap into (to-operating portions of the terminal contacts aforementioned.

\ The portion 43 of the insulating block is preferably milled or otherwise roughened to provide a suitable finger grip for inserting or removing the plug.

What I claim as new Letters Patent is 1* 1. In an attachment plug base, the combination with an insulating block having openings theret-hrough, a contact finger extending into one of said openings and having a hooked end overlapping a portion of said block. a shoulder on said contact finger, an insulating member overlapping said shoulder, a contact finger extending into another of said openings and having a hooked end overlapping a porticn of said insulating member, a screw threaded shell overlapping said insulating member and said last mentioned hooked end and means for permanently securing said shell to said bloe lr.

2. In an attachment plug base the combination with an insulating block having 0 enings therethrough, a contact finger extent ing into one of said openings and having a hooked end overlapping a portion of said block, a shoulder on said contact finger, an insulating member overlapping said shoulder, a contact finger extending into another and desire to secure by Y of said openings and having a hooked end overlapping a portion of said insulating member, a screw threaded shell overlapping said insulating member and said last mentioned hooked end, means on said blo'ck cooperating with said parts to prevent relative lateral movement thereof, and means on said shell for engagement with said block to prevent relative longitudinal movement of said parts.

3. In an electric attachment plug base, an insulating block having openings therethrough, a projection on said lease, a contact finger in one of said openings having a bent end portion to engage said projection, a shoulder on said contact finger intermediate the ends thereot', an insulating member engaging said shoulder, a contact finger in another of said openings having a portion to engage said insulating member and the outer surface of said block, a metallic shell to engage certain of said parts and to hold all of the same i.1 position, and means to permanently secure said shell to said block.

4. In an electric attachment plug base, an insulating block having openings therethrough, a projection on said block having channels in alinement with said openings, a contact finger resting upon said projection and extending into one of said openings, an insulating member engaging a transverse shoulder on said contact finger intermediate the ends thereof, a second contact finger resting upon said insulating member and extending into another of said openings, a conducting shell adapted to slide over and clamp said parts in position, and an annular groove in said block into which the lower portion of said shell is adapted to be spun to thereby secure said parts in position.

5. An electric attachment plug base, comprising an insulating block having openings therethrough, contact fingers extending into said openings and loosely supported by said block, a screw-threaded conducting shell adapted to slide freely onto said block to clamp all of said. contact lingers in position, an annular groove in said block into which said shell projects to look all of said parts in position, and an insulating member adapted to separate one of said contact fingers from said shell.

6. An electric attachment plug base, comprising an insulating block having openings therethrough, contact fingers loosely supported by said block and extending into. said openings, a conducting shell adapted to slide freely over one end of said block and said contact fingers to clamp the latter to the former, an insulating disk interposed between one of said contact fingers and said shell, a plurality of channels in said block into which all of said parts are respectively adapted to fit to prevent relative lateral movement thereof, and an annular gr ave in said block into which a portion of said shell is adapted to be bent to prevent relative longitudinal movement of said parts.

7. In an electric attachment plug base, an insulating block having openings therein, contact. fingers extending into said openings, a conducting shell for clamping all of said contact fingers in position, cooperating means on said block and said shell to prevent relative rotation thereof, a separate insulating member interposed between one of said contact fingers and said shell, the other of said contact fingers having a portion interposed between said insulating member and said shell, and said block having a groove adapted to receive a flange on said shell to prevent 1 relative longitudinal movement of said parts.

In witness whereof, I have hereunto subscribed my name.

GEOPGE J. MEUER. 

